These are doing great in my zone 8a yard, where it is especially hot and dry, with soil that's mostly dry clay, most of the year. I bought two of these goji bushes here, and they came as dubious-looking little twigs in large paper cups, and one twig was broken. I planted them anyways, and in just two months they have both grown tremendously and branched out, and are now clearly (to the neighbors who probably thought I was planting sticks) going to become bushes. They indeed seem drought tolerant, as I only give them about an inch of water twice a week and it's 90-100 F and windy outside most days. I am excited to have found something that takes so well to this region with little maintenance and may buy a third one. I have bought plants from many online vendors, but the ones from here always seem to fare better than others, even of the same variety planted in the same place, so I highly recommend Holland Bulb Farms in general, in addition to this plant, if the plant is what you're looking for.
May 2022 - Crazy to think that it started off as a little stick in a cup! I planted it out about a month and a half ago, and it's already tripled in size. Looks very healthy and I can't wait for berries this summer!